1. Field
The present disclosure relates to a paper feeding apparatus. More particularly, the present disclosure relates to a paper feeding apparatus that can selectively supply a print medium from two paper feeding trays using a single motor and an image forming apparatus having the same.
2. Description of the Related Art
Image forming apparatuses including two or more paper feeding trays have been widely used.
In general, a conventional image forming apparatus including two paper feeding trays includes two pickup rollers and two feed rollers in order to pick up and convey print media loaded in each of the two paper feeding trays. Accordingly, the conventional image forming apparatus including the two paper feeding trays controls a rotational force being transmitted to the pickup roller and the feed roller of each of the two paper feeding trays to supply the print medium selectively from the two paper feeding trays to the image forming unit. Accordingly, the conventional image forming apparatus supplies the print medium in one of the two paper feeding trays to the image forming unit by controlling the pickup roller and the feed roller in a variety of ways.
For example, a single motor may be configured to drive two feed rollers disposed in the two paper feeding trays at the same time. In this case, a pickup roller disposed in each of the two paper feeding trays selectively picks up the print medium so that, even when the two feed rollers are rotated at the same time, the print medium picked up from only one of the two paper feeding trays is supplied to the image forming unit.
However, in such a structure, because the single motor rotates also the feed roller disposed in the paper feeding tray which does not need to supply the print medium, a large motor capacity that can drive the two feed rollers is required. Accordingly, there are problems that arise such as an increase in material cost resulting in increased manufacturing cost and increased noise. Also, power consumption is increased due to the rotation of the unnecessary feed roller, and the life of parts associated with the rotation of the feed roller, such as a feed roller, a shaft, a bush, etc., is reduced resulting in increased maintenance costs.
As another example, the two feed roller may be configured to be selectively driven using one motor and two electronic clutches. In detail, when the print medium is supplied from a first paper feeding tray, a first electronic clutch disposed at a first feed roller of the first paper feeding tray supplies power of the motor to the first feed roller, and a second electronic clutch disposed at a second feed roller of a second paper feeding tray blocks the power of the motor from being supplied to the second feed roller. On the contrary, when the print medium is supplied from the second paper feeding tray, the first electronic clutch disposed at the first feed roller of the first paper feeding tray blocks the power of the motor from being supplied to the first feed roller, and the second electronic clutch disposed at the second feed roller of the second paper feeding tray supplies the power of the motor to the second feed roller.
However, for such a structure, the two electronic clutches are required for the operation control of the two feed rollers. Accordingly, the power consumption is large because of the operation of the electronic clutch, and there is a risk of malfunction of the electronic clutch. Also, since the electronic clutch and additional space for installation of the electronic clutch are needed, there is a problem that the material cost is increased.
As another example, the two feed rollers may be configured to be driven separately by two motors. In detail, when the print medium is supplied from the first paper feeding tray, a first motor is driven to rotate the first feed roller and a second motor for the second feed roller is hold stationary. When the print medium is supplied from the second paper feeding tray, the second motor is driven to rotate the second feed roller and the first motor for the first feed roller is hold stationary.
However, for such a structure, since the additional motor and a space for installation of the additional motor are needed due to usage of the two motors compared to the case in which a single motor is used, there is a problem that the material cost is increased.
Accordingly, development of a paper feeding apparatus that can selectively supply a print medium from two paper feeding trays using a single motor and that can minimize the material cost and installation space has been identified as desirable by the inventors of the present disclosure.